Two sources familiar with the incident confirmed to CNN that Michael Turner hand-delivered the written request to Issa. Politico first reported the move on Monday.

If Issa, who is not seeking re-election, is deposed as a part of Turner's divorce case, it would mark an unusual and dramatic development for two lawmakers and colleagues who serve alongside each other in the House of Representatives.

Turner filed for divorce against his wife in May 2017, according to online filings in the Montgomery County Domestic Relations Court in Ohio reviewed by CNN. The couple married in December 2015 and did not have children together, per court documents.

Turner's stated cause for filing for divorce is "fraudulent contract," according to court filings. Under Ohio law, the term suggests that a marriage was fraudulent and should be grounds for divorce because one party concealed or misrepresented something material from the other prior to the marriage.

Majida Turner's lawyer, Sanford Ain, told CNN in a phone interview that even though Michael Turner was not directly alleging infidelity as cause for divorce, Ain believed rumors about infidelity were being spread.

"Any allegation of infidelity is really off the wall," Ain said. "I can't comment as to why anyone would make such an allegation, but you can reach your own conclusions as to why someone would make such a false allegation like that."

Ain also explicitly denied -- "without any question, full stop" -- that Majida Turner had an affair with Issa.

Michael Turner's lawyers did not respond to CNN's requests for comment. An Issa spokesperson also did not respond to a request for comment.

Several sources told CNN that the amount of time that Majida Turner and Issa appeared to spend together -- both before and after Michael Turner filed for divorce -- had become widely discussed on Capitol Hill and elsewhere in Washington.

A former Issa aide told CNN that Majida Turner was a constant presence at Issa's congressional office on the Hill, estimating that she appeared to show up there at least weekly. In fact, the aide said, Majida Turner was considered one of a few lobbyists whom aides considered to have "clear and prioritized access" to Issa.

Two sources close to Majida Turner and Issa said they have been attending events together in Washington for several years.